For the operation of a double-worm extruder, a transmission has been provided heretofore in which one of the worms is directly driven via a spur gear arranged on a coaxial shaft while the other worm, which has a coaxial shaft with a gear, is indirectly driven by the spur gear and a number of gears disposed in succession to form a gear train. Thus for the drive of the indirectly driven worm, two parallel shafts connected via respective gears with the spur gear are required and the two interconnected shafts each can be coupled with the other shaft and with the gear of a worm shaft.
This rather complex gearing system with its multiplicity of shafts in addition to the shafts coaxial with the worms, has the disadvantage that its disassembly is complex which makes repair and maintenance difficult, time-consuming and costly.